Conveyer mechanism for wrapping machines



3 Sheets-Sheet l J. A. MASON ET AL l/VVfN '01? 3.4. mmwwla. W B7 wam-,M, MM

CONVEYER MECHANISM FOR WRAPPING MACHINES Feb. 26, 1952 Filed s ept. 25, 1950 Q Q k EL 1952 J. A. MASON ET AL CONVEYER MECHANISM FOR WRAPPING MACHINES Filed Sept. 25, 1950 3 Sheets-Sheet 2 Feb. 26, 1952- J. A. MASON ETAL CONVEYER MECHANISM FOR WRAPPING MACHINES Filed Sept. 25, 1950 Patented Feb. 26, 1952 CONVEYER. MECHANISM FOR WRAPPlNG MACHINES James Arthur Mason and William Arthur Rofiey, Deptford, London, England, assignors to Molins Machine Company Limited, Deptford, London,

England, a British company Application September 25, 1950,, Serial No. 186,518 H In Great Britain September 2'1, 1949 As is well known, inmachines for wrapping articles of rectangular block shape it is usual to convey the articles through the wrapper applying and folding devices by pushers mounted at intervals on conveyors, for example endless chains. As a wrapper isfolded about an article the rear end of the partly folded wrapper usually extends backwards from the rear face of the article, the extending. portion being subsequently folded down on to said face to complete the closure. The conveyors are supported by, and driven by, wheels at each end of the conveyor run and as a pusher reaches the forward end or the upper run it turns round with the wheel at that end and disappears beneath the surface of the bed of the machine in which the conveyor is fitted. The partly wrapped article remains on the bed surface and is moved onwards by some other device where necessary.

It will be seen that as the pusher ceases to move the article and begins to turn with the conveyor wheel it would disarrange or tear the extending portion and to avoid this it is usual to provide mechanism whereby the pusher is tipped back at this position so that it retreats out of the enclosure formed by the extending portion. In order to permit these movements the pusher is pivoted to the conveyor, but is held in its operative position during its movement along the operative run of the conveyor by a system of rails or like guides which cease at the position where tipping back is to occur.

Further, as it is necessary that the article shall remain on the bed surface as the pusher passes beneath the bed surface a comparatively narrow slot is provided for the pusher to pass through so that the article can easily cross the slot.

Tipping back is largely effected by the reaction of the article which becomes effective as soon as the rails terminate and it will be seen that if a pusher is not moving an article it is likely that it will strike the far side of the slot through not tipping back quickly enough. This causes noise and wear on the pusher and the edge of the slot. In high speed machines the difference in reaction in a large article and a smaller one is sufilcient to cause said noise and wear. A conveyor mechanism constructed and operated in this manner will be termed "a conveyor mechanism of the kind described.

'2 claims; (01. 198-170 An object of the invention to avoid said noise and wear and this is effected by a conveyor mechanism of the kind described comprising a device which engages the pusher at the tippingback position and applies some of the force necessary to effect tipping-back said device being adjustable to regulate said force to compensate for changes in the conveyor load and speed. The device may comprise a lever or finger adapted to press resiliently on a part ,of the pusher andapply a turning moment to the pusher at the tipping back position. A spring'urged lever with its free end intercepting the pathjof said part is suitable. The spring may be adjustable to regulate the pressure and thus the turning moment.

One way of carrying the invention into effect will be described with reference to the accompanying drawings in which:

Figure 1 shows a side elevation of a fragment of a machine embodying the invention, in section on the line I-I, Figure 3;

Figure 2 is a plan of Figure 1;

Figure 3 is a section of Figure 1 on the line III-III.

Referring to the drawings the machine in question is a wrapping machine of the kind usedto apply wrappers to cigarette cartons of the slide and shell type. In this machine the conveyor comprises a pair of chains 1 running beneath the surface of the machine bed 2 and spaced apart from one another as far as the bed will permit to allow room for the wrapping material to be fed downwards through a slot in the bed in the usual manner. The chains run on pairs of sprocket wheels 3, mounted at each end of the conveyor run and are bridged at regular intervals by pusher carriers 4. Between the chains at each pusher position is a rod or spindle 5 connected at each end to a chain by suitable plates 6.. On this rod is pivoted a carrier 4 which extends almost from one chain to the other and at the middle of the carrier is a bracket 1 which is fashioned into the actual pushing device 8. This arrangement gives a robust, well-mounted pusher. As the pusher travels along on the upper or operative run of the conveyor it is maintained in article engaging position by rails 9 mounted beneath the bed and engaging the ends III of the bridge.

At the tip-back position the rails cease and the pusher is tipped back partly by gravity and partly by reaction from the article.

At one side of the pusher a suitable surface of the bridge has aligned therewith a lever H 7 3 extending lengthwise of and pivoted at l2 to the machinev bed and having its free end near the tip back position. The lever is pulled downwards by a tension spring I3 attached thereto. The other end of the spring is attached to a screw l4 carrying a nut l5 so that the tension can be adjusted. The operative part of the lever may be shaped to the form of a wiper. A stop 1-6 limits the downward movement of the lever H.

As the pusher reaches the position "Where, owing to the absence of the rails, it can tip back, said bridge surface is engaged by the wiper or end of the lever and the spring pressure issuch that the pusher tips back without st'rileing the far side of the slot provided in the bed for the pusher to pass through. A v

If a machine is to run "empty, as for testing, or if the size and weight of the article changes,

the nutis adjusted to regulate the pressure which is easily done as it is only necessary to increase the tension until the noise ceases.

In order to prevent the :pusher fromswinging around the spindle too far in the direction opposite to the tipping direction the ends of the bridge may comprise convex grooves 11 adapted to *eng'age stop rpins F8 on the aforesaid chain plates and limit the possible movement of the pusher. Similar stop pins marked 19 can eng'age concavecurves 20 in the bridge ends to limit forward swin'ging of the pusher so that it can up 'on to the bed at the other end of the conveyor. The lever ,Il may be duplicated as shown.

What we claim "as our invention and desire to secure by Letters :Patent is:

1. In a conveyor mechanism for wrapping machines of the type having a machine bed and a conveyor for moving articles along the bed for wrapping operations, the combination with pusher-s pivoted to said conveyor, guide means engaging said pushers to retain "the latter in article engaging position over the operative portion of the conveyor run, and a device supported on said bed and positioned to yieldably engage and retard said pushers as the latter pass successively beyond the operative position of the conveyors -ior tipping said pushers back out of "article engaging position, and means for adjusting the force applied by said device to said pushers.

2, .A conveyor mechanism as claimed in claim l wherein said device comprises a lever adapted to press resiliently on a part. of the pusher, and apply a turning moment to the pusher at the tipping back position, spring means acting between said lever and bed, and meansrfor adjust- REFERENCES CITED The following references are of record in the file of this patent: V

UNITED STATES PATENTS Number Name :Date

1,740,582 Farmer Dec. 24, 1929 2,546,072 

